extra-keys = [[ \
  {key: ESC, popup: {macro: "CTRL g", display: "C-g"}}, \
  {key: CTRL, popup: {macro: "CTRL x", display: "C-x"}}, \
  {key: ALT, popup: {macro: "ALT x", display: "M-x"}}, \
  {key: TAB}, \
  {key: DEL, popup: {macro: "CTRL k", display: C-k}}, \
  {key: LEFT, popup: HOME}, \
  {key: DOWN, popup: PGDN}, \
  {key: UP, popup: PGUP}, \
  {key: RIGHT, popup: END} \
]]